1. Field of the Invention
The present invention relates to an antenna device, and more particularly to an antenna device having a rotatable structure for allowing the antenna device to be freely rotated relative to the support object or device to selected angular directions.
2. Description of the Prior Art
Typical antenna devices comprise an antenna housing or member solidly attached or secured onto a telecommunicating facility or the other support objects or devices, and some of the antenna housings or members may include a telescopic structure for selectively extending out of the telecommunicating facility or the other support objects or devices.
For example, U.S. Pat. No. 2,850,305 to Chadowski et al. discloses one of the typical extensible automobile aerials including three sections extendible inwardly and outwardly relative to the automobile. However, the antenna may not be rotated relative to the automobile to selected angular positions, such that the typical extensible automobile aerial may not easily receive telecommunicating signals.
U.S. Pat. No. 6,791,501 to Maeda et al. discloses a typical vehicle roof mount antenna including an antenna rod to be rotatably secured to an antenna base with a joint assembly for allowing the antenna rod to be rotated relative to the antenna base to various angular directions. However, a complicated anchoring or securing structure or mechanism is required to be provided in the joint assembly for firmly securing the antenna rod to the antenna base, and thus a great expense is required for making or manufacturing the typical vehicle roof mount antenna.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional antenna devices for telecommunicating facilities.